Convertible mode vascular catheter system

ABSTRACT

An angioplasty catheter comprising a catheter shaft having a proximal portion and a distal end, an angioplasty balloon attached to the shaft at the distal end, a balloon inflation lumen extending through the shaft and communicating with the interior of the balloon, a guidewire lumen extending through the shaft and through the balloon for receiving a steerable guidewire, the guidewire lumen having an outside wall, wherein the guidewire lumen has a proximal opening located at a point normally outside of the patient during use of the catheter for insertion of a guidewire into the lumen, and a side port adapted to permit passage of a guidewire into the lumen through the outside wall of the guidewire lumen, the side port located distally of the proximal opening and at a point normally inside of the patient during use, and guidewire removing means in the outside wall of the guidewire lumen extending from the proximal opening to the side port for permitting a guidewire in the guidewire lumen to be moved laterally from the guidewire lumen through the outside wall of the guidewire lumen. Also disclosed are a removable “Y” connector and methods for using the catheter and for exchanging catheters and guidewires during vascular catheterization procedures.

RELATED APPLICATIONS

[0001] This application is a continuation of application Ser. No.07/714,642 filed Jun. 13, 1991, the disclosure of which is herebyincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] This invention relates to vascular catheters (such as angioplastycatheters) specially adapted for rapid-exchange of both the guidewireand the catheter during use. It also relates to the method of usingthose catheters.

[0003] Percutaneous transluminal coronary angioplasty (PTCA) has emergedas the major viable present alternative to bypass surgery forrevascularization of stenotic and occluded coronary arteries. Althoughtransluminal angioplasty has application in peripheral artery disease,it is most widely used in the treatment of coronary artery disease.Unlike bypass surgery, percutaneous angioplasty does not require generalanesthesia, cutting of the chest wall, extracorporeal perfusion, ortransfusion of blood. Percutaneous coronary angioplasty is not only lessinvasive and less traumatic to the patient, it is also less expensivebecause the angioplasty patient will have a shorter hospital stay andshorter post-procedure recovery time.

[0004] Percutaneous transluminal angioplasty is performed by making askin puncture with a specially-designed needle in one of the groins, andthen introducing a guiding catheter (typically 8 or 9 French size) intothe aorta and coronary artery orifice. A smaller caliber catheter whichhas a built-in inflatable and deflatable balloon of predetermined sizeand diameter is passed through the guiding catheter which is positionedin the opening of a target artery. This balloon catheter (with theballoon totally deflated by negative pressure) is advanced inside thetarget artery toward the point of obstruction that needs to be dilated.The guidewire plays an essential role in leading the balloon catheter tothe target coronary artery in safety and non-traumatic fashion. With theballoon portion of the catheter properly positioned inside theobstructed segment of the artery, under X-ray fluoroscopic observation,the balloon is inflated by injecting contrast media mixed with saline ata pressure sufficient to overcome the resistance of the arterioscleroticplaque of the obstructed segment.

[0005] By inflating the balloon in the stenosis multiple times over aperiod of between 10-30 seconds and one or two minutes (allowing bloodflow between inflations), the desired dilation of the obstructed segmentof the artery can be achieved. When the desired results have beenobtained by balloon inflations, the guiding catheter, the ballooncatheter (with the balloon completely deflated with negative pressure)and the guidewire are withdrawn from the artery and the patient and theprocedure is successfully terminated.

[0006] The size and diameter of the balloon to be used in a transluminalangioplasty should be approximately matched to the size and nativediameter of the obstructed segment of the artery to be dilated. If theballoon size and diameter is smaller than the native artery, the resultsof balloon angioplasty are suboptimal, requiring a second dilation witha larger-sized balloon, and if balloon size is too large for the nativeartery, complications may occur due to arterial wall damage.

[0007] During the angioplasty procedure, a guidewire is first advancedinto the desired location, after which the angioplasty catheter isadvanced over the guidewire. It is sometimes necessary to replace (orexchange) either the guidewire or the balloon catheter during theprocedure.

[0008] If the balloon is undersized, for example, the catheter must bewithdrawn and replaced with a larger balloon catheter in order to permitadequate dilatation of the lesion. With conventional over-the-wirecatheters, in which the guidewire lumen extends the entire length of thecatheter shaft, a guidewire extension (e.g., 145 cm long) must first beattached to the regular guidewire (e.g., 175 cm long) being used outsidethe patient before the catheter is withdrawn. This permits the distalend of guidewire to be held in position while the catheter is removedand a new catheter is exchanged. Usually, two to three operators areneeded to effect such a catheter exchange.

[0009] The catheter disclosed in U.S. Pat. No. 4,762,129 avoids thenecessity for extending the guidewire or exchange guidewire (e.g., 300cm in length) by having a short guidewire lumen that extendssubstantially only through the distal end of the catheter. This type ofcatheter is referred to herein as a rapid-exchange catheter. Thus, theguidewire is outside the catheter shaft for much of the catheter length,and is inside the catheter at only the distal end. The catheter can beexchanged without extending the 175 cm regular guidewire, and theexchange can be effected by one or two operators. However, this catheterhas a serious drawback of not being able to permit ready exchange ofguidewires. In clinical practice, the need for guidewire exchange ismore common.

[0010] Conventional over-the-wire angioplasty catheters, with aguidewire lumen extending their entire length, permit simple guidewireexchange. During angioplasty procedures, the guidewire tip may becomedamaged, may be needed of a different type of guidewire or may need tobe reshaped to complement the patient's vasculature. The guidewireexchange procedure is readily accomplished with such a conventionalover-the-wire catheter. However, with the rapid-exchange type catheterof U.S. Pat. No. 4,762,129, guidewire exchange requires complete removaland reinsertion of both the guidewire and the angioplasty catheter;thus, defeating the original goal of expedient advantage of therapid-exchange catheter.

[0011] Another disadvantage of the rapid-exchange catheter isbackbleeding. While the guidewire is being manipulated to select thetarget vessel or to cross the culprit lesion, the Tuehy-Borst adaptermust be loosened. This, in turn, permits backbleeding to occur.

[0012] Accordingly, there is a need for an angioplasty catheter thatpermits rapid-exchange of both the catheter and the guidewire. There isalso a need for a catheter that will permit the user to select the modeof usage between the rapid-exchange and the over-the-wire systems.

BRIEF SUMMARY OF THE INVENTION

[0013] In accordance with one aspect of the present invention, there isprovided an angioplasty catheter comprising a catheter shaft having aproximal portion and a distal end, an angioplasty balloon attached tothe shaft at the distal end, a balloon inflation lumen extending throughthe shaft and communicating with the interior of the balloon, aguidewire lumen extending through the shaft and through the balloon forreceiving a steerable guidewire, the guidewire lumen having an outsidewall, wherein the guidewire lumen has a proximal opening located at apoint normally outside of the patient during use of the catheter forinsertion of a guidewire into the lumen, and a side port adapted topermit passage of a guidewire into the lumen through the outside wall ofthe guidewire lumen, the side port located distally of the proximalopening and at a point normally inside of the patient during use, andguidewire removing means in the outside wall of the guidewire lumenextending from the proximal opening to the side port for permitting aguidewire in the guidewire lumen to be moved laterally from theguidewire lumen though the outside wall of the guidewire lumen. In oneembodiment, the side port is located adjacent to and proximally of theballoon, preferably within about 35 cm of the balloon. One embodiment ofthe guidewire removing means is a slit through the outside wall of thecatheter shaft. This slit may be continuous from the proximal opening tothe side port or may be discontinuous, forming a perforated line fromthe proximal opening to the side port. In another embodiment, theguidewire removing means is a weakened area of the wall of the guidewirelumen adapted to be severed for removal of the guidewire therethrough.One variation of the invention provides a second side port communicatingwith the interior of the guidewire lumen. Another provides a perfusionopening communicating with the interior of the guidewire lumen, theperfusion opening located between the side port and the balloon. Stillanother embodiment includes a “Y” connector at the proximal openinghaving an axial portion through which the balloon inflation lumenextends and a side portion through which the guidewire may be insertedinto the guidewire lumen, wherein at least a portion of the connectorcan be removed from the catheter shaft to permit a guidewire extendingthrough the connector and into the guidewire lumen to be removed throughthe guidewire removing means. The connector is advantageously adapted tobe separated longitudinally and at least a portion thereof removed fromthe catheter shaft. In one variation, the connector comprises twolongitudinally separable portions having first and second longitudinalsides on different sides of the catheter shaft, the portions beinghingedly joined at the first longitudinal side and separably joined atthe second longitudinal side.

[0014] Another embodiment of the present invention comprises anintravascular catheter comprising a catheter shaft having a proximal endand a distal end, wherein a portion of the catheter including the distalend is normally inside a patient during use and the proximal end isnormally outside the patient or outside the guiding catheter, aguidewire lumen extending through the shaft for receiving a steerableguidewire, wherein the guidewire lumen has an outside wall, and aproximal opening at the proximal end of the shaft for insertion of aguidewire into the lumen, and means formed in the outside wall of theguidewire lumen extending distally from the proximal opening to a pointnormally inside the patient during use of the catheter for permitting aguidewire in the guidewire lumen to be moved laterally from theguidewire lumen through the outside wall of the guidewire lumen. Theguidewire removing means may be a slit, fully formed or inchoate. Thecatheter preferably includes a side port through the outside wall of theguidewire lumen for passage of a guidewire into through the side of thecatheter shaft, the side port located distally of the proximal openingand normally inside of a patient during use of the catheter. In oneembodiment of the catheter, the guidewire removing means is a slit andthe slit is continuous from the proximal opening to the side port. Inanother, the guidewire removing means is a slit and the slit isdiscontinuous, forming a perforated line from the proximal opening tothe side port. In still another embodiment, the guidewire removing meansis a weakened area of the wall of the guidewire lumen adapted to besevered for removal of the guidewire therethrough. According to onemodification, the catheter may further comprise a second side portcommunicating with the interior of the guidewire lumen.

[0015] The present invention also includes a catheter for use in ananimal body with a guidewire, comprising a catheter shaft having aproximal end and a distal end with at least two lumens extendingtherethrough, and a “Y” connector surrounding at least a portion of theproximal end of the catheter shaft and having at least two arms, one armproviding an access channel into one of the lumens and another armproviding an access channel into another of the lumens, wherein the “Y”connector has at least two segments joined together in a separablemanner along a longitudinal line so that upon separation of thesegments, the “Y” connector no longer surrounds the portion of theproximal end of the catheter shaft. In one embodiment, upon separationof the segments, one of the segments is completely removable from thecatheter shaft. In another embodiment, upon separation of the segments,the connector is completely removable from the catheter shaft in such amanner that an elongate object extending through one arm of theconnector into a lumen of the catheter shaft can remain in the lumenduring such removal of the connector.

[0016] The invention further includes a method of removing a catheterduring a procedure involving vascular catheterization, comprising thesteps of providing a catheter of the type described above having aguidewire passing through the guidewire lumen from the proximal openingto the distal opening thereof and positioning the catheter in a patientwith the prximal end of the guidewire extending proximal opening,holding the proximal end of the guidewire to maintain the positioning ofthe guidewire in the patient while removing the catheter from thepatient by moving the guidewire laterally out of the guidewire lumenthrough the guidewire removing means until the entire catheter isoutside the patient and outside the guiding catheter and a portion ofthe guidewire is exposed at the distal end of the catheter, and thenholding the exposed portion of the guidewire and removing the catheteroff of the proximal end of the guidewire. The method may also includeinserting another catheter, with the guidewire in the guidewire lumen atthe distal portion of the catheter and either remaining in the guidewirelumen for the entire length of the catheter that is inside the patientduring use, or extending out through the side of the catheter andrunning parallel to the catheter proximal of the distal portion of thecatheter.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

[0017]FIG. 1 is a foreshortened plan view of a catheter according to thepresent invention.

[0018]FIG. 1A is a transverse cross section of the catheter of FIG. 1,taken along the line A-A.

[0019]FIG. 1B is a transverse cross section of the catheter of FIG. 1,taken along the line B-B.

[0020]FIG. 1C is a transverse cross section of the catheter of FIG. 1corresponding to FIG. 1B, but illustrating the opening of the guidewireremoving means.

[0021]FIG. 2 is a fragmentary view of a portion of the catheter shaft ofthe FIG. 1 catheter surrounding the proximal opening, illustrating onevariation of the guidewire removing means.

[0022]FIG. 3 is a longitudinal cross section of the catheter of FIG. 1taken along the line 3-3, illustrating the guidewire in place and thefunction of the guidewire removing means.

[0023]FIG. 4 is a cross sectional fragmentary perspective view of thecatheter of FIG. 1, taken along the line B-B, illustrating anothervariation of the guidewire removing means.

[0024]FIG. 5 is a longitudinal cross section corresponding to FIG. 3,illustrating movement of the guidewire laterally out of the guidewireremoving means.

[0025]FIG. 6 is a foreshortened longitudinal cross section of theproximal end of one embodiment of the catheter of the present invention.

[0026]FIG. 7 is a perspective view of a removable “Y” connector at theproximal end of the catheter shaft.

[0027]FIG. 8 is a detailed perspective view of a locking mechanism onthe “Y” connector of FIG. 7.

[0028]FIG. 9 is a transverse cross section taken along the line 9-9 inFIG. 7.

[0029]FIG. 10 is a detailed perspective view of another lockingmechanism on the “Y” connector of FIG. 7.

[0030]FIG. 11 is an exploded transverse cross section corresponding toFIG. 9, illustrating removal of the “Y” connector from the cathetershaft.

[0031]FIG. 12 is a perspective view of the distal end of the cathetershaft after removal of the “Y” connector, illustrating a sealing member.

[0032]FIG. 13 is a longitudinal cross section of the removable “Y”connector, taken along the line 13-13 in FIG. 7.

[0033]FIG. 14 is a longitudinal cross section of the entire catheter,taken along the line 13-13 in FIG. 7.

[0034]FIG. 15 corresponds to FIG. 14, except that the guidewire isillustrated in place in the guidewire lumen.

[0035] The foregoing summary, as well as the following detaileddescription of the preferred embodiments of the present invention, willbetter understood when read in conjunction with the appended drawings.For the purpose of illustrating the preferred embodiments of the presentinvention, there is shown in the drawings, embodiments which arepresently preferred. It should be understood, however, that the presentinvention is not limited to the arrangements and instrumentality shownin the attached drawings.

DETAILED DESCRIPTION OF THE INVENTION

[0036] A basic embodiment of the catheter of the present invention isillustrated in FIG. 1. A catheter 10 is provided with a catheter shaft12 extending from a proximal end 14 to a distal end 16. As shown moreclearly in FIG. 1B, the interior of the catheter shaft 12 has aguidewire lumen 20 and a balloon inflation lumen 22 extending throughthe catheter shaft 12.

[0037] The catheter 10 has an angioplasty balloon 24 at the distal end16 thereof. At the proximal end 14 of the catheter shaft 12, a ballooninflation connector 26 is provided in fluid communication with theballoon lumen 22. Fluid introduced into the proximal end of the ballooninflation connector 26 can travel through the balloon lumen 22 and intothe interior of the balloon 24 to inflate and deflate the balloon 24during an angioplasty procedure. The balloon inflation lumen 22terminates inside the balloon 24. The opposite end of the ballooninflation lumen 22 terminates inside the balloon inflation connector 26.

[0038] The guidewire lumen 20 is adapted to receive a steerableguidewire and has an outside wall 30 (shown in FIG. 1B).

[0039] A proximal opening 32 is provided through the outside wall 30 ofthe guidewire lumen 20. This proximal opening 32 is situated in theproximal portion of the catheter shaft 12 at a location sufficientlyclose to the proximal end 14 that it is normally outside of the patientduring the angioplasty (or other vascular procedure). Typically, theproximal opening 32 will be within 60 cm, preferably within about 40 cm,more preferable within about 30 cm of the proximal end 14 of thecatheter 10.

[0040] The balloon 24 is made in accordance with conventional techniquesfor fabricating angioplasty balloons. Preferably, it is either blownfrom the distal end 16 of the catheter shaft 12, or is blown or formedof a separate piece of material which is bonded to the distal end of 16of the catheter shaft 12. The balloon 24 may advantageously be formed ofrelative inelastic polymer material, such as polyethylene,polypropylene, polyvinylchloride, polyethylene terephthalate, and thelike.

[0041] The catheter shaft 12 is also provided with a side port 34 whichextends through the outside wall 30 of the guidewire lumen 20. The sideport 34 is located distally of the proximal opening 32, and is locatedat a point normally inside of the patient when the catheter is properlyplaced for performance of an angioplasty procedure. Preferably, the sideport 34 is located proximally of the balloon 24 and within 80 cm,preferably 60 cm, and more preferably about 40 cm of the balloon 24.

[0042] The catheter 10 of the present invention is provided with a meansfor removing a guidewire that is inside of the guidewire lumen out ofthe guidewire lumen 20 through the outside wall 30 of the guidewirelumen 20. If the catheter shaft 12 or the guidewire is considered toextend in a longitudinal or axial direction, this movement of theguidewire out of the guidewire lumen 20 can be considered as a sideways,radial, or transverse motion of the guidewire. The guidewire removingmeans 40 is adapted to form a slit through the outside wall 30 of theguidewire lumen 20 through which the guidewire may be removed frominside the guidewire lumen 20. The guidewire removing means 40 may be anactual slit cut entirely through the side wall 30 of the guidewire lumen20 as illustrated in FIG. 1C. Alternatively, it may an inchoate slitsuch as the weakened area illustrated in FIG. 1B. The guidewire removingmeans 40 may be cut entirely through the outside wall 30 of theguidewire lumen 20 only in certain sections, leaving other sections atleast partially intact, to form a sort of perforated line. It may beformed of a different material than the remainder of the catheter shaft12 and even of a different material than the adjacent portions of theoutside wall 30 of the guidewire lumen 20.

[0043] One advantage of having only an inchoate slit is that it preventsbackbleeding out of the guidewire removing means 40 during performanceof the procedure. It is possible, however, to use an inchoate slit foronly the portion of the guidewire removing means 40 that is outside ofthe guiding catheter in use. The remainder of the guidewire removingmeans 40 that is outside the patient and outside the guiding cathetercan be a fully formed slit or a perforated slit without creatingbackbleeding problems.

[0044] As illustrated in FIG. 2, the guidewire removing means 40 maycomprise a removable tear strip 42 defined by a pair of weakened lines44, 46 extending distally from the proximal opening 32.

[0045] The guidewire removing means 40 extends from the proximal opening32 distally along the length of the catheter shaft 12 to a point that isordinarily inside the patient when the catheter 10 is properly placedfor performance of an angioplasty procedure. Thus, the guidewireremoving means 40 begins at a point ordinarily outside the patient andoutside the guiding catheter upon proper placement of the catheter 10and extends distally to a point ordinarily inside the patient upon suchplacement. From another perspective, it can be said that the guidewireremoving means 40 extends distally for at least 40 cm, preferably atleast 60 or 70 cm, and more preferably at least 80, 90 or 100 cm.

[0046] The guidewire removing means 40 may advantageously extenddistally to the side port 34, and in one embodiment of the invention,may extend an additional distance distally beyond the side port 34. Theguidewire removing means 40 preferably terminates proximally of theballoon 24, and may be immediately adjacent the balloon 24 or may be 5cm, 10 cm, or more proximally of the balloon 24.

[0047] If the guidewire removing means 40 is not a slit prior to itsuse, it becomes a slit or opening after use, as illustrated in FIG. 1C.

[0048] The use of the catheter 10 of the present invention isillustrated in FIG. 3. In this longitudinal cross sectional view, thecatheter 10 is illustrated with a guidewire 50 in place in the guidewirelumen 20. The proximal portion of the guidewire 50 is outside of thecatheter 10. The guidewire 50 passes-through the proximal opening 32into the guidewire lumen 20, and is inside the guidewire lumen 20 forthe entire length of the catheter shaft 12 that extends distally fromthe proximal opening 32. The distal end of the guidewire 50 extends outof the distal end 16 of the catheter shaft 12.

[0049] When the guide wire is to be removed radially or laterally out ofthe guidewire lumen 20, the guidewire removing means 40 provides a slitor opening in the outside wall 30 of the guidewire lumen 20 throughwhich the guidewire 50 may be removed from the guidewire lumen 20. Thisslit or opening, if not fully formed, may be completed by cutting theoutside wall 30 of the guidewire lumen 20, by tearing or rupturing aweakened area in the outside wall 30, or by tearing loose a removablestrip (as illustrated in FIG. 2). In a preferred embodiment theguidewire removing means 40 is a weakened area that is fully opened onlywhen the guidewire 50 is removed through the guidewire removing means40. In one embodiment, the guidewire 50 is simply pulled through theoutside wall 30 of the guidewire lumen 20. Alternatively, as illustratedin FIG. 4, the catheter shaft 12 may be provided with a filament 52 inassociation with the guidewire removing means 40. The filament 52 may bea continuous fiber or strand extending along the length of the guidewireremoving means and inside at least a portion of the outside wall 30 ofthe guidewire lumen 20. When the filament 52 is pulled outwardly, ittears a slit into the outside wall 30 of the guidewire lumen 20.

[0050] In FIG. 3, the initial removal of the guidewire 50 through theguidewire removing mans 40 is illustrated in phantom. In that figure, aphantom guidewire 50 is illustrated extending through the outside wall30 of the guidewire lumen 20 at a point distally of the proximal opening32.

[0051] As illustrated in FIG. 5, the phantom guidewire 50 is pulledthrough the outside wall 30 of the guidewire lumen 20 until theguidewire 50 has been removed through the outside wall 30 up to the sideport 32. It will be understood, of course, that in accordance with thepresent invention, the guidewire 50 may be removed through the outsidewall 30 to a point proximal of or distal of the side port 34; however,in a preferred embodiment, the lateral removal out of the guidewirelumen 20 continues up to the side port 34.

[0052] It should be noted that the removal of the proximal portion ofthe guidewire 50 through the outside wall 30 can be accomplished withoutlongitudinal or axial movement of the distal portion of the guidewire50. Thus, in FIG. 3, the distal tip of the guidewire 50 is in the sameposition as in FIG. 5; however, in FIG. 5, the guidewire has beenremoved laterally through the guidewire removing means along a portionof the length of the catheter shaft 12.

[0053] In the simplest embodiment of the present invention the guidewirelumen 20 may be provided simply with a proximal opening 32, a side port34, and guidewire removing means 40 extending distally of the proximalopening 32 at least to the side port 34, and perhaps beyond.

[0054] However, more sophisticated versions of the present invention arealso contemplated. In one such embodiment, a distal side opening 54 maybe provided through the outside wall 30 of the guidewire lumen 20 toprovide access into the guidewire lumen 20 at a point distal of thesideport 34. The distal side opening 54 may be open in normal use;however, the distal side opening 54 is preferably covered with aremovable patch 56, as best seen in FIGS. 3 and 5. The removable patch56 is preferably made of foil, Mylar, aluminized or metalized Mylar, orother suitable material, and may be held in place with an adhesive. Theremovable patch 56 may be removed from the catheter shaft 12 to open upthe distal side opening 54 to permit extension of the guidewire 50through the distal side opening 54 or to permit use of the distal sideopening 54 as a perfusion opening. In one embodiment of the invention,the guidewire removing means 40 extends distally to the distal side ofthe distal side opening 54.

[0055] The portion of the guidewire lumen 20 located proximally of theproximal opening 32 is preferably closed, and may be filled with afiller 60 such as a polymer material formed in place or a styletinserted in a waterproof manner into the guidewire lumen 20, asillustrated in FIGS. 3 and 5.

[0056] In an alternative embodiment the invention, the catheter of FIG.1 is modified at its proximal end as illustrated in FIG. 6.Specifically, this particular catheter has a conventional “Y” connector62 at the proximal end 14 of the catheter shaft 12 has the ballooninflation connector 26 and a guidewire connector 64 at the two“branches” of the “Y”. The guidewire lumen 20 extends from the proximalend 14 of the catheter shaft 10 through the guidewire connector 64 andthe “Y” connector 62 and extends distally the length of the cathetershaft 12.

[0057] The proximal opening 32 is located distally of the “Y” connector62. The catheter 10 is provided with a sliding cover 66 that is axiallymovable to cover or uncover the proximal opening 32. The sliding cover66 is preferably an annular sleeve circling the catheter shaft 12 andaxially movable with respect thereto. The sliding cover 66 preferablyhas a soft sealing material 70 (such as a pliable closed cell polymerfoam, a silicone elastomer, or other suitable material) on its insidesurface to provide a seal against the catheter shaft 12. Ordinarily, thesliding cover 66 is over the proximal opening 32, closing and sealingthe proximal opening 32.

[0058] In an alternative embodiment, the sliding cover 66 may bereplaced by a removable covering (not illustrated) similar to theremovable patch 56 to close the proximal opening 32 until it is used.

[0059] In ordinary use, the guidewire 50 extends distally through theguidewire connector 64, the remainder of the “Y” connector 62, insidethe guidewire lumen 20, past the proximal opening 32, and out of thedistal end 16 of the catheter 10. When required (as will be explained inmore detail hereafter), the sliding cover 66 or other seal covering theproximal opening 32 is removed, the catheter 10 is maintained in placein the patient while the guidewire 50 is removed proximally out of theguidewire connector 64, and the guidewire 50 is then inserted throughthe proximal opening 32 until it is in the desired position. Then theguidewire 50 is removed out through the outside wall 30 of the guidewirelumen 20 as explained in more detail elsewhere. Removal of the guidewire50 through the outside wall of the catheter shaft 12 permits conversionof the catheter from an over-the-wire catheter to a rapid-exchangecatheter that can be removed from the patient without extension of theguidewire 50.

[0060] In the embodiment illustrated in FIG. 6, because a-conventionalguidewire connector 64 is ordinarily used, backbleeding during use iseliminated by tightening the Tuehy-Borst adapter (not shown) except whenmanipulating the guidewire 50. This is in contrast to the embodimentillustrated in FIG. 1, where some backbleeding might be expected.

[0061] In yet another embodiment of the invention, the guidewire removaland reinsertion explained in connection with FIG. 6 is eliminated byproviding a removable “Y” connector 80, illustrated in FIGS. 7-13.

[0062] The particular embodiment of removable “Y” connector illustratedin FIG. 7 provides an axially separable “Y” connector 80. The “Y”connector 80 is preferably molded of a relatively hard thermoplasticmaterial, and is adapted to fit concentrically around the cathetershaft. The removable “Y” connector 80 is formed of 2 (or more) pieceswhich are joined together along lines extending in the axial orlongitudinal direction of the catheter shaft 12. In the illustratedembodiment, the removable “Y” connector has an axial portion 82 throughwhich the balloon lumen 22 (and preferably the catheter shaft 12)extends. The removable “Y” connector 80 further has a guidewireconnector 64 extending proximally and at an angle outwardly from theaxial portion 82 of the removable “Y” connector 80.

[0063] The guidewire connector 64 of the removable “Y” connector 80 iscylindrical in shape and has a guidewire bore 84 extending therethrough.The guidewire bore 84 connects through the proximal opening 32 into theguidewire lumen 20, as best illustrated in FIG. 13.

[0064] The removable “Y” connector 80 is preferably formed of a firsthalf 86 and second half 90. The first half 86 and the second half 90each has a semi cylindrical recess 92, 94 extending axially along thelength of each half 86, 90 of the removable “Y” connector 80. The semicylindrical recesses 92, 94 are best illustrated in FIG. 11. When thefirst and second halves 86, 90 are joined together, the semi cylindricalrecesses 92, 94 together form a cylindrical recess through which thecatheter shaft 12 extends.

[0065] When the first and second halves 86, 90 are joined together onthe catheter shaft 12, they are joined at a first edge 96 and a secondedge 100 on opposite sides of the catheter shaft 12. The first andsecond edges 96, 100 of each half 86, 90 extend axially parallel to theaxis of the catheter shaft 12.

[0066] In a preferred embodiment of the invention, the first edges 96 ofthe first and second halves 86, 90 are joined by a hinge 102.Preferably, the hinge 102 is a “live” hinge; that is, a hinge formed ofa thin portion of the polymer material of which the removable “Y”connector 80 is formed. In a preferred embodiment, the hinge 102 extendsaxially the entire length of the first edge 96.

[0067] The second edges 100 of the first and second halves 86, 90 areseparably joined together by any appropriate connecting mechanism. Theillustrated mechanism is but one possibility. In the illustratedmechanism, the second edge 100 of the first and second halves 86, 90,comprises on each half a radially extending tab 104 running the lengthof the second edge 100. At the outside radial edge of the tabs 104 is aflange 106 formed so that, when the first and second halves 86, 90 aremated together at their second edges 100, the flanges 106 extend inopposite directions on the first and second halves 86, 90, forming a “T”shape in radial cross section as shown in FIG. 9.

[0068] An edge connector 110 is provided to hold the second edges 100 ofthe first and second halves 86, 90 together. The edge connector 110preferably extends the entire length of the second edges 100 and isformed with a “T” channel inside to lock together the tabs 104 andflanges 106 of the second edges 100 of the first and second halves 86,90. Thus, the “T” of the mated second edges of the first second edges100 of the first and second halves 86, 90 is adapted to slide inside the“T” channel of the edge connector 110. Once the connector 110 is placedon the “T” of the second edges, it may be locked in place using anyappropriate mechanism. In one embodiment, a first end 112 of theconnector is permanently closed to prevent movement of the edgeconnector 110 in one direction. The second end 114 of the edge connector110 may have a breakaway end 116, as illustrated in FIGS. 7 and 8. Thebreakaway end 116 is glued or otherwise connected to the remainder ofthe connector 110 in such a manner that it may be readily severed fromthe edge connector 110. This may be done by a rocking motion applied tothe breakaway end 116 as illustrated in by the arrows 120 in FIG. 7.Once the breakaway end 116 is removed as illustrated in FIG. 8, theconnector 110 may be moved axially in the direction indicated by arrow122 until the edge connector 110 is removed from the remainder of theremovable “Y” connector 80. 1691 Another method for locking the edgeconnector 110 onto the removable “Y” connector 80 is by use of a lockingpin 124 as illustrated in FIG. 10. The locking pin may extend throughthe edge connector 110 and the second edges 100 of the first and secondhalves 86, 90, to lock the edge connector 100 in place. When the pin 124is removed, the edge connector 110 may also be removed.

[0069] Although the pin 124 illustrated in FIG. 10 is circular, anyother suitable pin or locking device may similarly be used.

[0070] After the removal of the edge connector 110, the first and secondhalves 86, 90 may be removed from the catheter shaft 12 as illustratedin FIG. 11 by pivoting the second edges 100 away from each other. Theremovable “Y” connector 80 may then be slid proximally off the proximalend of the guidewire 50.

[0071] In a preferred embodiment of the invention, a seal 126 isprovided around the catheter shaft 12 as illustrated in FIG. 12. Theseal 126 prevents leakage between the removable “Y” connector 80 and thecatheter shaft 12, and is preferably formed of annular polymer materialsuch as elastomeric material or closed cell foam. The seal 126 ispreferably provided with an index feature 130 for preventing rotationalor longitudinal movement of the in-place “Y” connector 80 with respectto the catheter shaft 12. In the illustrated embodiment, the indexfeature 130 is an outwardly extending tab; however, the index feature130 could alternatively be a groove, a recess, a flange, or the like.The outwardly-extending index feature 130 illustrated in FIGS. 12 and 11can cooperate with a complimentary index receptacle 132 on the axialportion 82 of the removable “Y” connector 80.

[0072] The use of the removable “Y.” connector is further illustrated inFIGS. 14 and 15. The catheter 10 without the “Y” connector 80 in placeis illustrated in FIG. 14. A guidewire 50 is inserted, into the proximalopening 32 through the guidewire connector 64, as seen in FIG. 15. Theguidewire 50 extends the length of the catheter shaft 12 and out of thedistal end 16 of the catheter 10.

[0073] When the removable “Y” connector 80 is removed from the cathetershaft 12, the catheter 10 is properly illustrated in FIG. 3, and theguidewire 50 can be removed laterally through the outside wall 30 of theguidewire lumen 20 as illustrated in FIGS. 3 and 5, and as previouslyexplained.

[0074] Although the removable “Y” connector 80 has been discussed in thecontext of a particular preferred embodiment, it will be understood thatequivalent removable “Y” connectors can be provided in which only aportion (such as a strip) of the “Y” connector is removed from thecatheter shaft 12; or where there are more than two separable pieces ofthe “Y” connector; or where alternative latches or locking mechanismsare utilized to hold the removable “Y” connector together until removalis desired. Further, other mechanical features having equivalentfunction can be substituted for others of the various describedelements.

[0075] Methods of using the Convertible Mode Catheter

[0076] The catheter of the present invention may be used as arapid-exchange catheter with the guidewire 50 extending through the sideport 34 and out of the distal end 16 of the guidewire lumen 20.Alternatively, it may be used as a conventional over-the-wire catheterwith the guidewire 50 extending substantially the entire length of thecatheter shaft 12 from the proximal end (either through a conventional“Y” connector 62 or a removable “Y” connector 80 or through the proximalopening 32) distally through the entire length of the catheter shaft andout of the distal end thereof.

[0077] A revolutionary aspect of the catheter of the present inventionis that it may readily and rapidly be converted from one mode of use tothe other. Thus, it can be used first as a rapid-exchange catheter, withthe guidewire extending in the guidewire lumen 20 only from theside-port 34 to the distal end of the catheter. It can be converted fromthis rapid-exchange mode of use to conventional over-the-wire use simplyby removing the guidewire and, while maintaining the catheter 10 inplace in the patient, inserting a new guidewire 50 into the proximal endof the guidewire lumen 20 (through a “Y” connector or through theproximal opening 32) and extending the guidewire 50 out of the distalend of the catheter 10.

[0078] When the catheter of FIG. 4 is being used as a conventionalover-the-wire catheter, it can be converted into a rapid-exchangecatheter by removing the removable “Y” connector 80 (if used), and, withthe guidewire extending proximally out of the proximal opening 32,maintaining the guidewire 50 in position in the patient while moving theguidewire laterally out of the outside wall 30 of the guidewire lumen 20through the guidewire removing means 40 and simultaneously withdrawingthe catheter 10 proximally until the distal end 16 of the catheter 10 isoutside of the patient. During this portion of the procedure, theguidewire 50 is held by grasping it at the proximal end. Then theoperator may hold the guidewire 50 by grasping the portion of theguidewire 50 exposed at the distal end 16 of the catheter 10, remove thecatheter 10 off of the proximal end of the guidewire 50, and insert anew catheter 10 over the guidewire 50 while maintaining the position ofthe guidewire 50 in the patient. The insertion of the new catheter 10may be accomplished in rapid-exchange mode by retrograde insertion ofthe proximal end of the guidewire 50 through the distal end of thecatheter and out of the side port 34. The proximal end of the guidewireis then held while the catheter 10 is advanced back into position in thepatient. The catheter can then be used as a rapid-exchange catheter.Alternatively, if desired, the guidewire 50 may be removed with thecatheter maintained in position, and in a matter of seconds theguidewire may be reinserted through the proximal opening 32 or throughthe proximal end 14 of the catheter shaft 12 to convert the mode of useto conventional over-the-wire use.

[0079] Thus, it will be appreciated that the catheter of the presentinvention can easily be used in either a rapid-exchange mode or anover-the-wire mode; that conversion between modes of use may be readilyaccomplished; that guidewire exchange may be accomplished in either modeof use, and that catheter exchange when in either mode of use can beaccomplished without use of an extension guidewire; and that all of theforgoing conversions and modes of use can be accomplished whilemaintaining the positioning of either the guidewire or the catheter inthe patient.

[0080] Thus, one method of the present invention comprises inserting thecatheter of FIG. 1 into the patient with the guidewire 50 going throughthe proximal opening 32 and extending from that point distally throughthe entire remaining length of the catheter shaft 12 and out of thedistal end 16. The guidewire 50 can then be exchanged by removing it andreinserting it through the proximal opening 32. The catheter can beexchanged by holding the guidewire as explained above while peeling awaythe catheter laterally while withdrawing it so that the guidewire ispulled through the guidewire removing means 40 until the distal end ofthe catheter is outside the patient. The guidewire is then held distallyof the catheter and a new catheter is inserted, this time inrapid-exchange mode. Once that catheter is in place, the guidewire canbe rapidly exchanged (if desired) to convert the catheter back into theover-the-wire mode of use as explained above.

[0081] In another method of use, the catheter of FIG. 6 can be used.This catheter can be used with the guidewire in the side port or theproximal opening, as explained above, with the same catheter andguidewire exchanges possible. Moreover, it can be used with theguidewire extending through the entire length of the guidewire lumen 20through the guidewire connector 64. Exchange of the guidewire from theguidewire connector 64 to the proximal opening 32 and vice versa is alsocontemplated.

[0082] The identical modes of use explained in connection with the FIG.1 catheter can be used with the removable “Y” connector catheter ofFIGS. 7-15, except the guidewire passes simultaneously through theproximal opening 32 and the guidewire adapter 64 of the removable “Y”connector 80. Further, in these modes of use, the conversion fromover-the-wire use to rapid-exchange use will require removal of the “Y”connector 80 prior to and in addition to use of the guidewire removingmeans 40.

[0083] Although the present invention has been described in the contextof certain preferred embodiments, it is intended that the scope of thepresent patent be measured with reference with the appended claims andreasonable equivalence thereof.

[0084] While the invention has been described with reference to apreferred embodiment, it will be understood by those skilled in the artthat various changes may be made and equivalents may be substitutedwithout departing from the scope of the invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the invention without departing from its scope.Therefore, it is intended that the invention not be limited to theparticular embodiment disclosed, but that the invention will include allembodiments falling within the scope of the appended claims.

1. An angioplasty catheter comprising: a catheter shaft having aproximal end, a distal end, and an angioplasty balloon mounted on saidshaft near said distal end; a guidewire lumen extending through saidshaft adapted for receiving a steerable guidewire, wherein saidguidewire lumen has an outside wall and a permanently formed proximalopening at or near the proximal end of said shaft adapted for insertionof a guidewire into said guidewire lumen; and a slit in the outside wallof said guidewire lumen extending distally from said proximal opening atleast about 40 cm. for permitting a guidewire, when deployed in saidguidewire lumen to be moved laterally from the guidewire lumen throughthe outside wall of said guidewire lumen.
 2. The catheter of claim 1,wherein the proximal opening is formed in the side of the catheter at apoint distal of the proximal end of the catheter, further comprising aguidewire adapter in the proximal end of the catheter communicating withthe guidewire lumen, so that a guidewire can be inserted into theguidewire lumen at the proximal portion of the catheter either throughthe guidewire adapter or through the proximal opening.
 3. A method ofremoving a catheter during a procedure involving vascularcatheterization, comprising the steps of: providing a catheter accordingto claim 2 having a guidewire passing through said guidewire lumen fromone of the proximal opening and the guidewire adapter to the distalopening thereof and positioning said catheter in a patient; and removingthe guidewire while maintaining the positioning of the catheter andinserting said guidewire back into the guidewire lumen and out of thedistal end of the catheter through the other of the proximal opening andthe guidewire adapter.